1. Field of the Invention
The present invention relates to a drive control apparatus for a hybrid vehicle which can run in a low fuel-consumption mode, in particular, a hybrid vehicle having a generator driven by an engine, and an (electric) motor driven by the generator or a battery device.
Priority is claimed on Japanese Patent Application No. 2006-126712, filed Apr. 28, 2006, the content of which is incorporated herein by reference.
2. Description of the Related Art
In a known example of a hybrid vehicle, a front motor is coupled to a crank shaft of an engine which can operate in a cylinder stop (or idle) mode, the front motor is connected to front wheels via a front clutch, and a rear motor is connected to rear wheels via a rear clutch. In an engine running mode, the hybrid vehicle runs with the front clutch connected so as to drive the engine, and in a first EV running mode of the hybrid vehicle, the engine is stopped and the front clutch is disconnected while the rear clutch is connected, so as to stop the front motor and run by only using the rear motor. In a second EV running mode of the hybrid vehicle, the engine is operated in a cylinder stop mode, the front clutch is disconnected, and the rear clutch is connected, so as to drive the front motor and run by only using the rear motor.
In accordance with the above hybrid vehicle, fuel consumption can be reduced (i.e., improved) by enlarging a range or area in which the vehicle can run using only the motor while the engine is stopped (see Japanese Unexamined Patent Application, First Publication No. 2004-208477).
In the above conventional structure, fuel consumption can be improved by combining the enlargement of the running range using the motor with the cylinder stop operation. However, when the vehicle runs using only the motor, the motor may be used in an inefficient range.